Who knew reclining your seat on an airplane would become such a heated issue?

But all of a sudden, it has. In the past week, two U.S. planes made emergency landings after passengers fought over reclining their seats, including one on which a man used a gadget called a “knee defender” to block the seat in front of him from moving back. The contraption is banned on most airlines.

It’s not necessary to ask permission to recline, although some people do, she added. But it is a nice gesture to at least alert the person behind you that you’re going to lean back.

Don’t Freak Out

“I once had an older woman threaten to punch a young girl in the face if she pushed her chair back one more time,” Poole said.

Yeah – don’t do that.

Don’t Nag the Flight Attendant

“People ask us, can you tell this person to put their seat up?” Poole said. “It puts me in an awkward position because they don’t have to put their seat up. And if I tell one person, then it’s like a domino effect.”

Do Say Hello

It helps in the long run. Think about it – you’re less likely to complain about someone who smiled and said hello to you when you got on the plane, right?

“It used to be that you would get on an airplane and say hello to a person sitting next to you, so you have a little bit of a relationship going on,” Poole said. “That makes it easier if someone gets upset with a kid kicking, for example.” Or, with a reclined seat.

Do Put Your Seat Up When Told To

There’s a reason flight attendants ask passengers to put their seat up before landing, Poole said. It locks the seats in place so that if there’s an emergency evacuation, the person behind you can get out quickly.

But too many passengers ignore the rule, Poole said.

“It’s like nobody wants to or they think you’re kidding,” she said. “Every flight, I walk down the aisle and I’m thinking, I know these people have been on a flight before.”

So next time, please just put your seat up.

Don’t Be a Jerk

Poole suspects people are quicker to flip out on airplanes because they’re already stressed from the hassle of traveling, and also because they’re essentially anonymous, removed from their comfort zone.

“People are really stressed out, they’re really miserable, they don’t want to fly,” she said. “Anything makes people overreact. And I don’t blame them. I can see their pain as they walk down the aisle. But at the same time, it doesn’t give them the right to be childish.”